Beneficial insects: bug your bugs
by Karla Stange
Biological alternatives to chemical pesticides are gaining wide popularity
in the agri-cultural industry. Take advantage of these non-toxic techniques
in your backyard plot.
f you are a gardener, you understand heartbreak and
frustration. It's that pain you feel when you check the lush tomato plants
you lovingly tended all summer, only to find the bright red fruit blighted
with worm holes.
Your first angry response may be to grab the nearest
pesticide and spray away. But if you are like many other environmentally
sensitive people, the use of chemicals in the home garden may cause a pang
It's a tough decision. You can't live in peace with
the litte beasts that ruin your prized fruits, vegetables or flowers, but
you don't want to wantonly spread poison all over your yard either.
Beneficial insects may provide an ideal solution. You may already know about
some of these "Terminator" bugs: praying mantis, ladybugs, decollate
snails and beneficial nematodes. In addition to these faithful predators,
there's a whole army of lesser-known insects that can be ordered through
catalogs (see Call to action, below) to help you maintain order in your
The concept of using beneficial insects as "biocontrol"
is simple: increase the ratio of predators to prey and it will create a
natural balance that will protect your garden. When used in conjunction
with other new organic and non-toxic garden products like insecticidal soaps
and sticky traps, beneficial insects can provide efficient and environmentally
safe pest management.
Ag industry uses 'good' bugs
The beneficials that you find in commercial nurseries
have first been extensively tested on farms. Due to the growing public concern
over the use of pesticides, many growers have started searching for organic
ways to protect their crops. The agricultural industry currently uses many
benefical insects to control stubborn pests, and the trend is likely to
Don Domenigoni, an entomologist and Agricultural Standards
Investigator for the County of Riverside Agricultural Commission, believes
beneficials may be one of the key elements in a new system of biocontrol.
"If the growers can get an integrated pest management control program
going, it would not only benefit the environment, it's also going to benefit
them economically." Growers are faced with tougher pests that have
developed a resistance to chemicals, so they are turning to beneficials
instead of larger and more expensive amounts of pesticides.
To spray or not to spray
The insects that have been proven to work in the field
are slowly entering the commercial market, and recreational gardeners have
shown increasing interest. "Once people know about biocontrol, there
will be a demand for it," said Domenigoni, "because that's what
the Green movement is all about - consumer support for products that won't
hurt the environment."
You may think of your backyard garden as a peaceful
paradise, but under the leaves and within the soil, there's a raging battle
for survival. An army of aphids, worms and beetles struggle to find food,
which, unfortunately, may be your neat little rows of peas and carrots.
One way to get rid of the pests instantly is to use pesticides. Sure, this
gets rid of the bugs, but it also may contaminate the water your cat drinks,
or kill the birds who eat the dead pests, or even poison the air you and
your children breathe. One bottle of pesticide can create a dangerous chain
Lou Diaz, Manager of Mission Hills Nursery in San Diego,
is concerned with the commercial misuse of pesticides. "People don't
always read the warning labels that say 'Don't release near streams or ponds,'
or they don't wear protective clothing when they spray. There can be some
dangerous exposure." For people who are concerned about chemicals in
their environment, beneficial insects can be the key to a new way of protecting
home gardens. "But you pretty much have to decide one way or the other
- beneficials and biopesticides or chemicals," said Diaz. "The
reason is that you'll kill off your beneficials along with the harmful pests
if you use even the smallest amount of pesticides."
Using biocontol measures, on the other hand, means that
your actions are in tune with the natural cycle of life. While pesticides
are like an atom bomb, eradicating all insect life for an extended period
of time, beneficial insects work like little hitmen, selecting out only
the pests that are causing problems in your garden. "Like any predator-prey
relationship, you have peaks and valleys in the populations. Bio-control
is never absoute or eradicative. The beneficials are never going to kill
totally all of their prey. But they will kill enough to keep the pests from
destroying your crops," said Domenigoni.
If you are a person who demands quick results, however,
using biocontrol methods may be frustrating. "For people who want instant
gratification, biocontrol is probably not a good idea. While pesticides
take a few minutes to kill the pests, beneficials take a couple of weeks.
But if you set out beneficials while the plants are young, before a pest
problem is out of control, then you'll see good results," said Domenigoni.
Buying the best bugs
It may seem strange to spend money on a carton of ladybugs,
or a little box of decollate ("carniverous") snails at your local
nursery. There is also a parasitic wasp on the market now where you buy
an empty box, send it to a certain address, and it comes back to you full
of egg cases ready to be hatched.
For those who are a little squeamish, handling insects
may be a major detriment to starting a biocontrol program. But consider
the rewards of using, for example, beneficial nematodes to protect your
lawn. "A lot of people have problems with grubs in their lawns during
the summer," said Diaz. "Then you have two problems, because grubs
attract skunks, who like to dig for them. Beneficial nematodes get rid of
the grubs, protect the lawn and prevent skunks from dining on your property."
According to Diaz, nursery customers are now asking
for certain beneficials by name, instead of automatically reaching for pesticides.
Decollate snails, which eat the common brown garden snail, are popular because
snails can be difficult to control, and baits and sprays may not get rid
of the problem. Decollate snails also offer another benefit: after they
have eaten the garden snail population down, they feed on organic material
like dead leaves, which adds to the natural composting process.
Most of the beneficial insects are available in nurseries
only in the spring and summer seasons, but now is a good time to plan a
system of biocontrol for next year. "Talk to a local nursery-person
who is familiar with the products. They can help you figure out which pest
you're trying to get rid of, then recommend the appropriate beneficial insect,"
You may be thinking: "I hate bugs, why would I
want to add more to my garden?" With a good system of bio-control,
you won't even notice the tiny insects that will protect your plants. There
won't be any black clouds of insects swarming around you, invading the peace
of your garden. In fact, you'll feel more relaxed, knowing that you don't
have to keep the kids or pets away from areas previously sprayed with chemicals.
Here are a few tips on how to use beneficial insects
in your garden:
1. Target your pest.
Think about what fruits, vegetables, or flowers you are going
to plant, and do some investigative work on which pests in your specific
area tend to be a problem. With the help of a nurseryperson, choose a beneficial
insect that will go after these pests. Think of it as a food chain game
matching predator to prey.
2. Create an attractive environment
For bugs, this means plentiful food, water and shelter. One
way to encourage the process is to have a permanent border of weeds or native
plants around the area you want to protect. Although cultivating weeds may
not appeal to your aesthetic sense, it will help to keep your garden protected
and free of chemicals. An occasional sprinkling of water on these sheltering
weeds will provide enough moisture for your beneficial insects to thrive.
If you create a good environment, your beneficials may breed and reproduce,
which will create a perennial army of "hitmen" bugs.
3. Avoid any chemicals
Make sure you haven't sprayed or baited for snails in the last
six months before you set out decollate snails. Remember, if there is lingering
pesticide on your plants and soil, your beneficials will suffer.
4. Plant a succession of crops
For vegetable growers, it's a good idea to plant a series of
fruits and vegetables throughout the year. This provides a continuous pest
supply as a food source for your beneficials. For example, once your lettuce
crop is done, they can move on to tomatoes, and then cabbage, and so on.
This will prevent your beneficials from abandoning your garden en masse
and moving on to your neighbor's yard once they have eaten a pest population
5. Release during early spring to mid-summer
Insects don't like extreme heat or cold, so you'll get the best
results if you release them during the mild weather seasons (although with
San Diego weather, you may be able to release them year-round). It's also
better to release the insects in the early morning or early evening, when
temperatures are cool and there is moisture in the air.
6. Watch for the first signs of pests
Don't wait until a pest problem is out of control. Due to the
slow process of reducing a population through natural means, you'll probably
lose some of your crops. Set the beneficials out either before the problem
occurs (this is where the investigative work pays off) when the plants are
young, or when you see the very first signs of damage to the plants.
7. Give yourself a pat on the back.
You deserve a little thanks for doing your part to protect
the environment. If every gardener starts with their own back yard, it will
make a big difference in our quality of life.
Call to action ... What you can do
Call or visit your local nurseries. Many can provide
you with professional advice and a variety of pesticide alternatives. Common
products include ladybugs and "bt" (a bacillus spray particularly
effective against worms and catterpillars).
In the book Sustaining the Earth, Debra Dadd-Redalia
calls The Bio-Integral Resource Center "the very best source for practical
information on the least toxic methods for managing pests." Members
can get advice by mail or phone about virtually any pest problem. The group
publishes a newsletter and has a number of pamphlets on pests. You can write
them at: P.O. Box 7414, Berkeley, CA 94707, or call (415) 524-2467.
Gardens Alive! is probably your number-one source for
organic garden products. While many beneficial insects can be found at your
local nursery, if you really get interested in biocontrol, this little catalog
offers several "killer" beneficial insects that you can't find
in nurseries. You can choose from green lacewings, whitefly parasite and
Gardens Alive also carries many innovative non-chemical
pest control products, like traps, sticky bars, and insecticidal soaps.
To order this catalog ,call (812) 537-8650.
Karla Stange is an editor for the Times-Advocate in Escondido, an
environmental reporter, and a free-lance writer. Raised in Hemet, CA, she
moved to San Diego 6 years ago and now lives in Golden Hill.